I feel like you’re taking the author out of context. His point is that without the open-source work fewer opportunities would exist for the person doing it. So

I feel like you’re taking the author out of context. His point is that without the open-source work fewer opportunities would exist for the person doing it. So it’s a bit disingenuous to act like you do all of this “purely for free” when it’s more like “self-marketing”. I get how imposing on people doing the former can be unreasonable, but asking things of people doing the later seems quite fair.